Cylindrical lock combination changer

ABSTRACT

An apparatus and method for changing the combination on a cylindrical lock. An adaptor has a blank key with ribs slidably mounted thereto. A keyhole in the adaptor receives an original ribbed key which positions the ribs on the blank key in a manner identical to the positioning of the ribs on the original key. The blank key inserted in the cylindrical lock is then turned and the original key withdrawn from the adaptor. A new key is then inserted in the adaptor relocating the tumblers within the cylindrical lock and changing the combination of the lock. The adaptor and new key are rotated back to an original position and withdrawn from the lock.

D United States Patent 1 [111 3,868,838 Zimmerman et al. 1 Mar. 4, 1975[54] CYLINDRICAL LOCK COMBINATION 2,424,514 7/1947 Sterner 70/383CHANGER 3,817,066 6/1974 Pearson 70/363 [75] Inventors: Earl L.Zimmerman, Indianapolis; Primary E \.aminer Robert L Wolfe RonaldHomeler plamfleld both Attorney, Agent, or Fir/77Woodard, Weikart, ofEmhardt & Naughton [73] Assignee: Code Key International Corporation,Indianapolis, Ind. [57] ABSTRACT [22] Filed: 23, 1973 An apparatus andmethod for changing the combination on a cylindrical lock. An adaptorhas a blank key 1 1 pp bio-14133471 with ribs slidably mounted thereto.A keyhole in the adaptor receives an original ribbed key which posi- 52us. c1 70/383, 70/411, 70/447 hens the ribs Oh the blank key in a manneridentical to 51 Int. Cl. E05b 25/00 the Positioning of the ribs theOriginal The [58] Field of Search 70/363, 382, 383, 384, blank heyinserted in the eyhhdrieel leek is 70/385 400 409 411 431 447 turned andthe original key withdrawn from the adaptor. A new key is then insertedin the adaptor relocat- [56] References Cited ing the tumblers withinthe cylindrical lock and changing the combination of the lock. Theadaptor and new UNITED STATES PATENTS key are rotated back to anoriginal position and with- 2,021,443 11/1935 Deutsch 70/383 drawn fromthe lock 2,044,534 6/1936 Lej'oowiczm. 70/383 2,423,734 7/1947 Sterner70/411 7 Claims, 7 Drawing Figures PATENTED 4 sum 1 ar g PATENTEUHARM975 3.868.838

sum 2 gr 3 FIG, 5

CYLINDRICAL LOCK COMBINATION CHANGER BACKGROUND OF THE INVENTION 1.Field of the Invention This invention is in the field of cylindricalcombination locks.

2. Description of the Prior Art The U5. Pat. Nos. 2,423,734 and2,424,514 issued to B. Sterner disclose a ribbed key which is insertableinto a cylindrical combination lock. The lock includes spring biasedbits which are positioned by the ribs of the key to a location adjacenttumblers within the lock thereby allowing rotation of the inner cylinderwith respect to the outer cylinder of the lock. It is desirable toprovide an apparatus and method which will conveniently allow for thechange of the combination of the cylindrical lock without necessitatingremoval of the lock. Disclosed herein is such a method and apparatus.

SUMMARY OF THE INVENTION One embodiment of the present invention is anadaptor insertable into a first keyhole ofa cylindrical combination lockto change the combination thereof corresponding from an originallongitudinally ribbed key to a different longitudinally ribbed keycomprising a main body having a blank key fittable into the keyhole anda key receiving housing attached to the blank key, the housing having asecond keyhole sized to receive the original key and subsequent to theremoval of the original key to then receive the different key, the blankkey having at least one side with channels extending longitudinallythereon, a plurality of bits slidably mounted in said channels, aplurality of pushers connected to the bits and projecting into thesecond keyhole to contact ends of ribs of a ribbed key inserted into thesecond keyhole, and means within the main body and in contact with thepushers being operable to position the bits on the blank key in a manneridentical to the positioning of ribs on a ribbed key inserted into thesecond keyhole.

Another embodiment of the present invention is a method of changing thecombination on a cylindrical lock from the combination corresponding toan original key to a combination corresponding to a new key, the lockincludes a fixed outer cylinder, an inner cylinder rotatably mounted inthe outer cylinder and having a first keyhole, tumblers slidably mountedin the outer cylinder, adjustable bits slidably mounted in the innercylinder, pusher means connected to the bits and projecting into thekeyhole to be contacted by ribs of a ribbed key inserted into thekeyhole and operable to align the bits with the tumblers to allowrotation of the inner cylinder, comprising the steps of inserting anadaptor having a blank key with movable ribs into the keyhole, insertingthe original key into the adaptor aligning the bits with the tumblers,turning the original key from the original position to rotate the innercylinder and position the bits on the tumblers, withdrawing the originalkey from the keyhole, inserting the new key into the adaptor to locatethe bits and tumblers to a position corresponding to the newcombination, turning the new key to rotate the inner cylinder back tothe original position, and withdrawing the adaptor from the keyhole.

It is an object of the present invention to provide an apparatus forchanging the combination of a cylindrical combination lock.

A further object of the present invention is to provide a method forchanging the combination of a cylindrical combination lock.

Related objects and advantages of the present invention will be apparentfrom the following description.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a key for usewith the lock of FIG. 3.

FIG. 2 is a cross sectional view taken along the line 22 of FIG. 1 andviewed in the direction of the arrows.

FIG. 3 is a fragmentary longitudinal section taken through a cylindricallock with only one pusher and tumbler illustrated for purposes ofclarity.

FIG. 4 is a transverse section taken along the lines 4--4 of FIG. 3 andviewed in the direction of the arrows. I

FIG. 5 is a side view of an adaptor incorporating the present invention.

FIG. 6 is a top view of the adaptor of FIG. 5.

FIG. 7 is a cross sectional view taken along the line 7-7 of FIG. 5 andviewed in the direction of the arrows with a key shown inserted into theadaptor and the adaptor inserted in the lock of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT For the purposes of promoting anunderstanding of the principles of the invention, reference will now bemade to the embodiment illustrated in the drawings and specific languagewill be used to describe the same. It will nevertheless be understoodthat no limitation of the scope of the invention is thereby intended,such alterations and further modifications in the illustrated device,and such further applications of the principles of the invention asillustrated therein being contemplated as would normally occur to oneskilled in the art to which the invention relates.

Referring now to FIGS. 1 and 2,. there is shown a key which is disclosedin the US. Pat. No. 2,423,734 issued to B. Sterner. Said US. Pat. No.2,423,734 is hereby incorporated by reference. Key 10 includes a handleportion 11 which is connected to the shank portion 12. Shank portion 12includes a plurality of grooves 13 which are positioned on each side ofshank 12. A plurality of ribs 14 are mounted to shank l2 and arepositioned within grooves 13. In the embodiment of the key shown inFIGS. 1 and 2, the opposite sides of shank 12 are each provided with 3separate grooves providing a total of six grooves 13. Each groove isprovided with a separate rib 14 providing a total of six ribs. The ribsextend from the handle portion of the key towards end 15 with each ribterminating at a specific location between the ends of the keycorresponding to the combination of the lock shown in FIGS. 3 and 4.

Lock (FIGS. 3 and 4) is disclosed in the US. Pat. No. 2,424,514 issuedto B. Sterner. US. Pat. No. 2,424,514 is hereby incorporated byreference. Lock 20 is cylindrical in configuration and includes a fixedouter cylinder 21 and an inner cylinder 22 rotatably mounted in theouter cylinder. Inner cylinder 22 is provided with a keyhole 23 forreceiving key 10. A plurality of grooves 24 extend longitudinally on theinner surface of outer cylinder 21 and are spaced equally around keyhole23. A plurality of tumblers 25 are slidably mounted in grooves 24. Aplurality of adjustable bits 26 are slidably mounted to inner cylinder22 with each adjustable bit being integrally connected by walls 27 to aplurality of pushers 28 slidably mounted to the inner cylinder andprojecting into keyhole 23. In the embodiment shown in FIGS. 3 and 4, atotal of six tumblers 25, six adjustable bits 26, and six pushers 28 areemployed. Likewise, six ribs are provided on key for contacting the sixpushers 28 as the key is inserted in keyhole 23 thereby aligning theadjustable bits 26 with the tumblers 25 to allow rotation of the innercylinder with respect to the. outer cylinder as described in theaforementioned U.S. Pat. No. 2,424,514. In the event that only four ribsare provided on key 10, then only four tumblers, four adjustable bitsand four pushers are provided in lock 20.

Lock may be locked or unlocked by turning key 10 while the key ispositioned within the lock. The ribs 14 of key 10 align the adjustablebits 26 with tumblers to allow rotation of the inner cylinder withrespect to the outer cylinder. In the event that ribs 14 are not of thecorrect length to position adjustable bits 26 adjacent to tumblers 25,then the adjustable bits will contact the tumblers and prevent rotationof the inner cylinder with respect to the outer cylinder.

Shown in FIGS. 5 through 7, is an adaptor 30 which is used to change thepositioning of tumblers 25 and thereby allow for the changing of thecombination of the cylindrical lock. Adaptor 30 includes a main bodyhaving a blank key 31 fittable into keyhole 23 of lock 20. A keyreceiving housing 32 is attached to blank key 31 and is provided with asecond keyhole 33 sized to receive key 10.

Blank key 31 is provided with a pair of opposite sides 34 and 35 witheach opposite side having three grooves extending the length thereof.For example, side 35 is provided with three grooves 36 for receivingthree slidably mounted ribs 37 which are normally positioned withinhousing 32. Each rib 37 includes an enlarged head 38 with a helicalspring 39 positioned between each head 38 and the inside surface 40 ofwall 41 of housing 32. Each rib 37 projects through a spring 39. Wall 40is provided with suitable apertures to allow ribs 37 to slidetherethrough as springs 39 are compressed. Heads 38 project into keyhole33 (FIG. 6) so as to contact the ends of the ribs provided on the keyinserted into keyhole 33. A separate helical spring 39 is provided foreach rib 37. The helical springs normally urge ribs 37 away from blankkey 31 and into housing 32. The springs are yieldable to allow the ribsof a ribbed key inserted into keyhole 33 to contact heads 38 and pushribs 37 outwardly in grooves 36. In the embodiment shown in FIGS. 4through 7, three ribs are provided on each side of blank key 31 to allowuse of the adaptor with the lock shown in FIGS. 3 and 4. In the eventthat the cylindrical lock is provided with only four tumblers and fouradjustable bits, then only four ribs are provided on blank key 31 ofadaptor 30.

The method of changing the combination of lock 20 from the combinationcorresponding to an original key to a combination of a new key has as afirst step the insertion ol' adaptor 30 into keyhole 23 of the lock. Theoriginal key is then inserted into adaptor 30 positioning ribs 37 alongthe length of blank key 31 in a manner identical to the positioningofthe ribs along the original key such as shown in FIG. 7. As a result,the adjustable hits 26 will be aligned with tumblers 25 in a manneridentical to the alignment existing if the original key were inserteddirectly into cylindrical lock 20 instead of being inserted into adaptor30 which has been inserted into the cylindrical lock. The original keyis then turned along with adaptor 30 to rotate the inner cylinder andposition the adjustable bits 26 on tumblers 25 as shown in FIG. 7. Theoriginal key is then withdrawn from adaptor 30 and a new key is insertedinto the adaptor. Prior to the insertion of the new key, the helicalsprings 42 (FIG. 3) within lock 20 will force tumblers 25 and adjustablebits 26 to a position immediately adjacent the forward wall 43 of thelock thereby erasing the combination existing within the lockcorresponding to the original key. Thus, when a new key is inserted intothe adaptor, ribs 37 will move to a position along blank key 31identical to the positioning of the ribs of the new key. Ribs 37 willcontact pushers 28 and move the adjustable bits 26 and tumblers 25 to anew position corresponding to the new combination of the new keyinserted into the adaptor. The new key and adaptor may then be rotatedback to the original position and the adaptor withdrawn from keyhole 23thereby locking the new combination within the lock corresponding to thepositioning of the ribs on the new key. The new key may be withdrawnfrom adaptor 30 immediately prior to withdrawing the adaptor from thelock and immediately subsequent to rotating the new key and adaptor backto the original position.

Blank key 31 is attached to surface 47 of wall 41 and is provided withopposite edges 44 and 45 with aligned notches 46 formed thereon. Notches46 engage a disc surrounding the keyhole 23 of lock 20. The disc notshown in FIG. 3 is slotted at the opposite edges of the keyhole to allowinsertion of the key and to prevent removal of the key other than whenthe key inserted into keyhole 23 is in the original position.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, the same is to be considered asillustrative and not restrictive in character, it being understood thatonly the preferred embodiment has been shown and de scribed and that allchanges and modifications that come within the spirit of the inventionare desired to be protected.

The invention claimed is:

1. An adaptor insertable into a first keyhole of a cylindricalcombination lock to change the combination thereof corresponding from anoriginal longitudinally ribbed key to a different longitudinally ribbedkey comprising:

a main body having a blank key fittable into said keyhole and a keyreceiving housing attached to said blank key, said housing having asecond keyhole sized to receive said original key and subsequent to theremoval of said original key to then receive said different key, saidblank key having at least one side with channels extendinglongitudinally thereon;

a plurality of bits slidably mounted in said channels;

a plurality of pushers connected to said bits and projecting into saidsecond keyhole to contact ends of ribs of a ribbed key inserted intosaid second keyhole; and,

means within said main body and in contact with said pushers beingoperable to position said bits on said blank key in a manner identicalto the positioning of ribs on a ribbed key inserted into said secondkeyhole.

2. The adaptor of claim 1 wherein:

said means includes a plurality of helical springs mounted in saidhousing normally urging said pushers away from said blank key and saidbits into said housing but yieldable to allow ribs of a ribbed keyinserted into said second keyhole to contact said pushers and push saidbits outwardly in said channels.

3. The adaptor of claim 2 wherein:

said blank key has a side opposite said one side with additionalchannels extending longitudinally thereon and further comprising:

a plurality of additional bits slidably mounted in said additionalchannels;

a plurality of additional pushers connected to said additional bits andprojecting into said second keyhole to contact ends of ribs of a ribbedkey inserted into said second keyhole; and,

additional helical springs within said main body and in contact withsaid additional pushers, said additional helical springs normally urgingsaid additional pushers away from said blank key and said additionalbits into said housing but yieldable to allow ribs of a ribbed keyinserted into said second keyhole to contact said additional pushers andpush said additional bits outwardly in said additional channels.

4. The adaptor of claim 3 wherein:

said blank key has opposite edges each with an aligned notch formedthereon adjacent said housmg;

said pushers and said additional pushers are each an enlarged buttonhead each integrally mounted to an inner end of a separate one of saidbits, said bits each project through one of said helical springs whereassaid additional bits each project through one of said additional helicalsprings, said helical springs and said additional helical springs arepositioned between a button head and said blank key. 5. A method ofchanging the combination on a cylindrical lock from the combinationcorresponding to an original key to a combination corresponding to a newkey, said lock includes a fixed outer cylinder, an inner cylinderrotatably mounted in said outer cylinder and having a first keyhole,tumblers slidably mounted in said outer cylinder, adjustable bitsslidably mounted in said inner cylinder, pusher means connected to saidbits and projecting into said keyhole to be contacted by ribs of aribbed key inserted into said keyhole and operable to align said bitswith said tumblers to allow rotation of said inner cylinder, comprisingthe steps of:

inserting an adaptor having a blank key with movable ribs into saidkeyhole; inserting said original key into said adaptor aligning saidbits with said tumblers; turning said original key from the originalposition to rotate said inner cylinder and. position said bits on saidtumblers; withdrawing said original key from said keyhole; insertingsaid new key into said adaptor to locate said bits and tumblers to aposition corresponding to said new combination; turning said new key torotate said inner cylinder back to said original position; and,withdrawing said adaptor from said keyhole. 6. The method of claim 5wherein: said inserting step of said original key includes pushing ribsof said original key against said pusher means; and, said inserting stepof said new key includes pushing ribs of said new key against saidpusher means. 7. The method of claim 6 comprising the additional step ofwithdrawing said new key from said adaptor subsequent to the step ofturning said new key.

1. An adaptor insertable into a first keyhole of a cylindrical combination lock to change the combination thereof corresponding from an original longitudinally ribbed key to a different longitudinally ribbed key comprising: a main body having a blank key fittable into said keyhole and a key receiving housing attached to said blank key, said housing having a second keyhole sized to receive said original key and subsequent to the removal of said original key to then receive said different key, said blank key having at least one side with channels extending longitudinally thereon; a plurality of bits slidably mounted in said channels; a plurality of pushers connected to said bits and projecting into said second keyhole to contact ends of ribs of a ribbed key inserted into said second keyhole; and, means within said main body and in contact with said pushers being operable to position said bits on said blank key in a manner identical to the positioning of ribs on a ribbed key inserted into said second keyhole.
 2. The adaptor of claim 1 wherein: said means includes a plurality of helical springs mounted in said housing normally urging said pushers away from said blank key and said bits into said housing but yieldable to allow ribs of a ribbed key inserted into said second keyhole to contact said pushers and push said bits outwardly in said channels.
 3. The adaptor of claim 2 wherein: said blank key has a side opposite said one side with additional channels extending longitudinally thereon and further comprising: a plurality of additional bits slidably mounted in said additional channels; a plurality of additional pushers connected to said additional bits and projecting into said second keyhole to contact ends of ribs of a ribbed key inserted into said second keyhole; and, additional helical springs within said main body and in contact with said additional pushers, said additional helical springs normally urging said additional pushers away from said blank key and said additional bits into said housing but yieldable to allow ribs of a ribbed key inserted into said second keyhole to contact said additional pushers and push said additional bits outwardly in said additional channels.
 4. The adaptor of claim 3 wherein: said blank key has opposite edges each with an aligned notch formed thereon adjacent said housing; said pushers and said additional pushers are each an enlarged button head each integrally mounted to an inner end of a separate one of said bits, said bits each project through one of said helical springs whereas said additional bits each project through one of said additional helical springs, said helical springs and said additional helical springs are positioned between a button head and said blank key.
 5. A method of changing the combination on a cylindrical lock from the combination corresponding to an original key to a combination corresponding to a new key, said lock includes a fixed outer cylinder, an inner cylinder rotatably mounted in said outer cylinder and having a first keyhole, tumblers slidably mounted in said outer cylinder, adjustable bits slidably mounted in said inner cylinder, pusher means connected to said bits and projecting into said keyhole to be contacted by ribs of a ribbed key inserted into said keyhole and operable to align said bits with said tumblers to allow rotation of said inner cylinder, comprising the steps of: inserting an adaptor having a blank key with movable ribs into said keyhole; inserting said original key into said adaptor aligning said bits with said tumblers; turning said original key from the original position to rotate said inner cylinder and position said bits on said tumblers; withdrawing said original key from said keyhole; inserting said new key into said adaptor to locate said bits and tumblers to a position corresponding to said new combination; turning said new key to rotate said inner cylinder back to said original position; and, withdrawing said adaptor from said keyhole.
 6. The method of claim 5 wherein: said inserting step of said original key includes pushing ribs of said original key against said pusher means; and, said inserting step of said new key includes pushing ribs of said new key against said pusher means.
 7. The method of claim 6 comprising the additional step of withdrawing said new key from said adaptor subsequent to the step of turning said new key. 